A screen, such as a display panel of a Thin Film Transistor-Liquid Crystal Display (TFT-LCD), usually comprises an active area and a non-active area located at periphery of the active area. A gate driver is in the non-active area for performing line-by-line scan on gate lines. The present gate driver usually adopts a Gate Driver on Array (GOA) design. A GOA circuit is usually formed by integrating a gate switching circuit mainly composed of Thin Film Transistors (TFTs) on a display panel. As such, a narrow frame design can be realized without binding a gate driving integrated circuit (IC).